In a world where personal connections are transmitted through unique vocal frequencies, you play as an investigator navigating a city where individuals mysteriously vanish after uttering their last greetings. Armed with a voice-modulating device known as the Hello-Hacker, your task is to uncover the truth behind these disappearances while piecing together the relationships of the missing. Engage with quirky characters, decipher clues hidden in conversations, and manipulate speech patterns to unlock side quests. The choices you make shape the story, leading you to multiple endings, each revealing a different facet of the city's secrets.